Our research goals during the coming year are: (1) to map the structural gene encoding nucleoside diphosphokinase, (2) to establish the routes by which nucleoside triphosphates, other than ATP are synthesized from corresponding nucleoside diphosphates, (3) to determine the route of synthesis of dCTP as outlined in the original grant proposal, (4) to determine the number and function of the genes encoded by Tn10, and (5) to determine the physiological consequences of starvation of a cell for dCTP. (6) If time permits, we will estimate the relative contribution of phosphoryolytic and hydrolytic turnover of mRNA using the various mutants in nucleotide metabolism that we now have available.